As far as I know the releases cycle is not fixed, but rather relies on the amount of modifications/bug fixes and the time available for maintainer(s) to officially release a new version.

If you whish to always run the latest version you've better regularly build yourself from sources on the github repository, or run YaCy as a docker container (images built automatically from the latest sources are available here : https://hub.docker.com/r/luccioman/yacy/ [^]).